Gaseous conduction lamp



June 4, 1940. F. ALEXANDER 2,203,482

GASEOUS CONDUCTION LAMP Filed Jan. 27, 1931 V c M41 mm F'atented June 4,1940 PATENT OFFICE GASEOUS CONDUCTION LAMP Focsancanu Alexander. NewYork. N. Y.. assignor,

by mesnc assignments. to Argco Tube and Television Corporation. acorporation of Delaware Application January 27. 1931, Serial No. 511.516

3 Claims.

My invention concerns a lamp in which luminescence is brought about byan electric discharge or are through a gaseous medium.

One object of my invention is to provide in a device of that kind meansheating the electrodes in order to condition the lamp for the aredischarge.

Another object of my invention is to provide electric resistance meansheating the electrodes to a point at which the electronic emission ofthe electrodes is sufiicient to carry an electric discharge or are, forthe purpose of starting the operation of that lamp or whenever the heatde- 1 velopcd in such electrodes by an are or discharge falls short ofsustaining such a discharge or are.

Another object of my invention is electrically to coordinate in agaseous conduction lamp the electrode heating means with the electrodesso that the lamp may be started as well as be kept in operation from asuitable source of current supply. without the use of auxiliarymechanism or electrical devices.

Another object of this invention is to provide a gaseous conduction lampwhich lends itself to a construction in a large range of sizes, andparticularly of very small intensities.

A further object of my invention is to provide a vapor lamp which may beoperated from a transformer of simple design and of a capacity whichdoes not have to be in excess of the normal current requirements of thelamp.

Still another object of this invention provides for a layout. in whichthe electrodes are heated to bring about a discharg but are not heatedto a point of disintegration at which disintegrated parts of anelectrode distort the spectrum of the luminescent gases.

A further object is to supply a vapor lamp which may be constructed tobe connected to a standard current supply. the auxiliary electricoquipment being limited to a resistance or choke device.

Another object of my invention is to provide a gaseous conduction lampwhich may be adapted to any shape of bulb and which may be used in anyposition of operation.

Other objects of my invention will become apparent from a perusal of thefollowing description and the appended drawing. in which,

Fig. 1 shows a sectioned. schematic view of a lamp of my invention.

Fig. 2 shows a modification of my improvements in a similar view.

Fig. 3 shows a similar view of another modifi 5 cation of my'invention.

From a constant current transformer 6 two leads 1 sealedly extend intoan enclosure 8. where they connect to the two electrodes 9. Theelectrodes arc exemplarily given the shape of extended cups and are madeof a material which 6 :mits electrons when heat is supplied thereto,such as tungsten, or a material which is coated with a compound of ametal which increases electronic emission under heat such as an oxide ofa metal of the alkaline earths. Thegaseous 10 charge of the enclosuremay consist of any gas which will be inert with respect to theelectrodes during operation: the charge may also comprise solids orliquids which are gasified under the heat or operation of the lamp andwhich confer 15 particular characteristics upon the radiation of thelamp.

Through the length of the electrodes 9 extend clcctric resistors H!which are mounted upon the bases of the electrodes and which thusconnect an to the source of electric current supply. The free ends ofthe resistors it) are connected to each other by way of another resistorH. by means of which a suitable potential drop is brought about betweenthe resistors ill.

The electric current supplied to the lamp heats the resistor l0, whichin turn heats the electrodes 9 until the temperature of the electrodeshas been raised to a point where the electronic emission of theelectrodes permits a discharge or are from 30 one electrode to theother. (When direct current is used, I may confine myself to heating thecathode: or only one electrode may be heated when the lamp is to serveas a rectifier.) At or below the potential at which the current is sup-5 plied to the electrodes and to the resistors ill. the discharge or aretogether with the heat supplied by resistors, l0 further increases theelectronic emission of the electrodes so that the current supplied fromthe transformer G will ultimately 40 be substantially completelyconsumed in the are or discharge. the current passing through the threeresistors l0 and II dropping to a low value. When at any point of theoperation the heat of the arc discharge is insufllclent for sustaining45 said discharge or when there is a temporary interruption in thecurrent supply. causing a drop in the heat of the electrode. the currentwill again flow through the resistors and reestablish the necessaryelectron emitting heat of the elec- 5 trodes. The potential drop acrossthe three resisters is of such magnitude as to bring about a dischargebetween the electrodes, after they have been sufiiciently heated. Theresistors I0 may therefore be directly connected by a conductor [2 whentheir combined resistance equals the potential necessary to strike theare between the electrodes.

Such an arrangement is shown in Fig. 2 where the electrodes have theshape of longitudinal shields iii. The shields l3 are connected to thelead-in wires by conductors H. The enclosure l5 has in this modificationa fancy, arbitrarily semi-circular shape. An A. C. generator 16 isindicated as astandard source of current supply. The resistor isconnected in series with that source across the tube, said resistordetermining the maximum current consumption possible in the lamp.

The lamp of the modification of Fig. 3 is excited and controlled byapparatus similar to that used in Fig. 2 for that purpose. Theelectrodes have in this instance the form of electric heating elements'8, said electrodes being directly heated by the current passingtherethrough. The conductor l9 extends upon the outside of the enclosure20 and connects to theelectrodes l8 at two lead-in points 2| in theenclosure. The resistor 22 is comprised in the conductor l9 and has suchan electric resistance, that the potential across its terminals duringthe operation of the lamp is of the order necessary to maintain agaseous arc discharge between the electrodes IS. The resistance ofelements I8 is of an order to produce sufiicient electronic emission forthe striking of an arc therebetween.

If the resistance of elements I8 is such as not only to heat saidelements to the point of the necessary electronic discharge, but is ofsuch order that the sum of the potential drops across said elementsequals or exceeds the voltage necessary to maintain a gaseous arcdischarge therebetween, the resistor 22 may be omitted, and thearrangement then becomes similar to that of Fig. 2.

An example of the arrangement of the lamp of the type shown in Fig. 1will illustrate that,

such a lamp can be operated from a lowly rated source of constantcurrent: The lamp is filled with argon at 2 mm. pressure and a drop ofmercury iscontained therein. The containers 8 are made of nickel and arecoated with barium oxide. 25 volts are applied to the lamp and heat thetwo tungsten filaments ill to an incandescent heat under a potentialdrop of four volts, respectively, the balance of 17 volts being consumedin resistor H. An arc across the electrodes is established within-ashort period of time, due to argon ionization. Subsequently the heatvolatilizes mercury and this results in, a discharge having thecharacteristics of a mercury arc. Under these final operating conditionsthe cur rent is 2 amperes and has a potential drop of 13 volts. Sincethe pressure of the mercury vapors is comparatively low, the' totalradiation of the lamp contains a comparatively high percentage ofultraviolet rays.

While I have shown and described my invention with some degree ofparticularity, it will be realized that other modifications and changesmay be resorted to under special conditions. I

. therefore do not wish to be limited and restricted to the exactdetails shown and described. but reserve the right to make such changesand modifications as may fairly fall within the scope of the subjectmatter now being claimed.

I claim:

1. A gaseous conduction lamp comprising a gas container, three electricresistance elements in series, the second of which is arranged outsideof said container, whereas the first and third elements are comprised inthe electrodes in the lamp and serve to heat the electrodes.

2. An electric discharge lamp comprising an envelope containing anionizable gas, a pair of electrodes within said envelope, 9. lead-in foreach electrode, a heater for each electrode connected at one end to itsrespective electrode, a connecting member between the other end of theheaters, and a pair of lead-ins for said connecting memher, saidconnecting member being disposed outside of said envelope.

3. In a gaseous conduction lamp, a sealed envelope, a pair of electrodesin said envelope each comprising electric resistance means for heatingsaid electrode, said electrodes being placed for a gaseous dischargetherebetween and being provided with connections outside of saidenvelope for connection to a source of current, and electricalconnecting means extending substantially outside of said envelope andconnecting said resistance means of said pair of electrodes in serieswith each other.

FOCSANEANU ALEXANDER.

DISCLAIMER 2,203,482.Focsaneanu Alexander, New York, N. Y. GnsnousOONDUCTION LAMP Patent dated June 4, 1940. Disclaimer filed Aug. 21,1945, by the assignee General Electric Company.

Hereby disclaims from the scope of claims 1, 2 and 3 of said LettersPatent any gaseous conduction lamp having a starting circuit whichincludes auxiliary mechanism in said starting circuit to start the lampin operation or auxiliary mechanism in said starting circuit to startand keep the lamp in operation.

[Oficial Gazette October 9, 1945.]

